Abstract-A novel focused active microwave system is investigated for detecting tumors in the breast. In contrast to X-ray and ultrasound modalities, the method reviewed here exploits the breast-tissue physical properties unique to the microwave spectrum, namely, the translucent nature of normal breast tissues and the high dielectric contrast between malignant tumors and surrounding lesion-free normal breast tissues. The system uses a pulsed confocal technique and time-gating to enhance the detection of tumors while suppressing the effects of tissue heterogeneity and absorption. Using published data for the dielectric properties of normal breast tissues and malignant tumors, we have conducted a two-dimensional (2-D) finite-difference timedomain (FDTD) computational electromagnetics analysis of the system. The FDTD simulations showed that tumors as small as 2 mm in diameter could be robustly detected in the presence of the background clutter generated by the heterogeneity of the surrounding normal tissue. Lateral spatial resolution of the tumor location was found to be about 0.5 cm.

We are investigating a new ultrawide-band (UWB) microwave radar technology to detect and image early-stage malignant breast tumors that are often invisible to X rays. In this paper, we present the methodology and initial results of three-dimensional (3-D) finite-difference time-domain (FDTD) simulations. The discussion concentrates on the design of a single resistively loaded bowtie antenna element of a proposed confocal sensor array. We present the reflection, radiation, and scattering properties of the electromagnetic pulse radiated by the antenna element within a homogeneous, layered half-space model of the human breast and the polarization and frequencyresponse characteristics of generic tumor shapes. We conclude that the dynamic range of a sensor array comprised of such elements in conjunction with existing microwave equipment is adequate to detect small cancerous tumors usually missed by X-ray mammography. Index Terms-Antenna array, cancer, FDTD methods. I. INTRODUCTION A potentially important strategy for reducing breast cancer mortality is the detection of early-stage tumors [1]. X-ray mammography is currently the most effective screening modality for detecting clinically occult breast cancers. However, approximately 10-30% of breast cancers are missed by mammography [2], [3]. The significant number of false negatives may be attributed to the limitations of mammography in: 1) assessing dense glandular tissue and regions located close to the chest wall or underarm and 2) imaging very early-stage tumors that do not yet exhibit microcalcifications. Another concern is the high rate of false positives in screening mammograms [3], [4]. These statistics indicate a critical need for complementary modalities with high sensitivity and specificity for early detection through low-cost screening. Ultrasound and contrast-enhanced MRI are effective in the diagnostic evaluation of mammographically detected breast lesions. However,

Background: Pharmacological approaches are widely used for post-traumatic stress disorder (PTSD) despite uncertainty over efficacy. Objectives: To determine the efficacy of all pharmacological approaches, including monotherapy, augmentation and head-to-head approaches (drug versus drug, drug versus psychotherapy), in reducing PTSD symptom severity. Method: A systematic review and meta-analysis of randomised controlled trials were undertaken; 115 studies were included. Results: Selective serotonin reuptake inhibitors (SSRIs) were found to be statistically superior to placebo in reduction of PTSD symptoms but the effect size was small (standardised mean difference −0.28, 95% CI −0.39 to −0.17). For individual monotherapy agents compared to placebo in two or more studies, we found small statistically significant evidence for the antidepressants fluoxetine, paroxetine, sertraline, venlafaxine and the antipsychotic quetiapine. For pharmacological augmentation, we found small statistically significant evidence for prazosin and risperidone. Conclusions: Some medications have a small positive effect on reducing PTSD symptom severity and can be considered as potential monotherapy treatments; these include fluoxetine, paroxetine, sertraline, venlafaxine and quetiapine. Two medications, prazosin and risperidone, also have a small positive effect when used to augment pharmacological monotherapy. There was no evidence of superiority for one intervention over another in the small number of head-to-head comparison studies. Tratamiento farmacologico para el trastorno de estres postraumatico: una revision sistematica y metanalisis de monoterapia, potenciacion y abordajes comparativos Antecedentes: Los abordajes farmacológicos se usan ampliamente para el trastorno de estrés postraumático (TEPT) a pesar de su eficacia incierta. Objetivos: Determinar la eficacia de todos los abordajes farmacológicos, incluyendo monoterapia, potenciación y abordajes comparativos (droga versus droga, droga versus psicoterapia), en la reducción de la severidad de los síntomas de TEPT. Método: Se llevó a cabo una revisión sistemática y metanálisis de estudios controlados aleatorizados; se incluyeron 115 estudios. Resultados: Se encontró que los inhibidores selectivos de la recaptación de serotonina (ISRSs) fueron estadísticamente superiores a placebo en la reducción de los síntomas de TEPT, pero el tamaño de efecto fue pequeño (diferencia media estandarizada −0.28, IC 95% −0.39 a −0.17). Para agentes en monoterapia individuales comparados con placebo en dos o más estudios, encontramos para los antidepresivos fluoxetina, paroxetina, sertralina, venlafaxina y el antipsicótico quetiapina una evidencia estadísticamente significativa pequeña. Para la potenciación farmacológica, encontramos para prazosina y risperidona, evidencia estadísticamente significativa pequeña. Conclusiones: Algunos medicamentos tienen un efecto positivo pequeño en la reducción de la severidad de los síntomas de TEPT y pueden ser considerados como potenciales tratamientos en monoterap...

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